Pressure switches are incorporated in a wide variety of applications for controlling a device based on a pre-determined pressure. For example, if a pressure switch is in communication with a fluid (liquid or gas) supply, the pressure switch can activate once the pressure supply reaches a pre-determined pressure threshold. Similarly, the pressure switch may de-actuate at pressures substantially below the pre-determined pressure threshold. Conversely, the pressure switch could optionally de-actuate when the pressure supply reaches the pre-determined pressure threshold and actuate when the pressure supply returns to below the pre-determined pressure threshold. Thus, pressure switches can be used to determine whether the fluid pressure is above or below a pre-determined pressure threshold.
One type of pressure switch uses a diaphragm. Pressure can act on one side of the diaphragm and an actuating switch can be provided on the other side of the diaphragm. The diaphragm can have a known stiffness which only flexes when a pressure above a pre-determined value is applied. Therefore, in prior art pressure switches, a given diaphragm is only effective for fluid pressures within a relatively small range. If the fluid pressure acting on the diaphragm is normally above the threshold value for the diaphragm, the pressure switch may not be operable. Similarly, if the fluid pressure acting on the diaphragm never attains the pre-determined value, the diaphragm may not flex and actuate the switch.
A problem with prior art diaphragm pressure switches is providing a diaphragm that is operable across a broad range of pressures. Another problem in the past has been providing a pressure switch with a diaphragm that incorporates a minimum number of parts at a low cost. The present invention overcomes these difficulties by providing a pressure switch with an integrated diaphragm. Furthermore, a single integrated diaphragm may be used across a broad range of pressures. In addition, the pressure switch of the present invention comprises minimal parts, making it economical to produce.